The Atom & Isotopes Packet #5 Chapter #2

Introduction to Atoms & Elements The smallest particle of an element **Elements are composed of atoms Element A substance composed of atoms having an identical number of protons in each nucleus. A substance that cannot be decomposed into simpler substances 1/13/2019 1:17:32 PM

Structure of Atom Two “broad” regions Interior Exterior Nucleus Electron Shell 1/13/2019 1:17:32 PM

Structure of Atom II Nucleus Interior part of the atom that contains Protons Have a positive charge Neutrons Have a neutral charge (no charge) 1/13/2019 1:17:32 PM

Structure of Atom III Electron Shell/Cloud Exterior region of the atom where electrons are found Electrons Negative charge Surround the atom The most outer electrons are used in the formation of chemical bonds. 1/13/2019 1:17:32 PM

The Periodic Chart

The Periodic Chart The Periodic Chart Is a list of all elements, but more importantly, it lists the characteristics of the atoms that make up each element. The list provides the number of protons, the atomic number, and the atomic mass of the atom found within a particular element.

The Periodic Chart & Elements The Equation The Periodic Chart shows the atomic number and atomic mass of the elements Atomic Number (Z) The number of protons in the nucleus of an atom Atomic Mass (A) The absolute atomic mass of an atom Equation A = Z + N N = number of neutrons in the nucleus of an atom 1/13/2019 1:17:32 PM

Isotopes

Isotopes One of two or more atoms with very similar properties. An isotope is an atom that has the same atomic number but a different atomic mass. In order to change the atomic mass, if the atomic number is the same, then the number of neutrons must be changed.

Isotopes Isotopes are used to help prove the theory of evolution. Carbon-14 dating.

Review

Review Atom Interior Protons Positive Charge Neutrons Neutral Charge Exterior Electrons Negative Charge Helps make chemical bonds Remember, an element is composed of similar atoms A = Z + N

Review II Isotopes Used to support theory of evolution Atoms with same atomic number Atoms with different atomic mass Used to support theory of evolution